A cassette of the above-mentioned type is used, in particular, for imaging with X-rays, for example, for medical purposes. The cassette serves to receive a storage fluorescent screen in which an image generated with X-ray radiation can be stored latently. The storage fluorescent screen is kept in the cassette during transportation and normally is removed from the cassette only for reading out the stored image.
Known from EP 1 324 117 A1 is a cassette for receiving such a storage fluorescent screen which is provided with an opening through which the storage fluorescent screen can be inserted in the cassette or removed therefrom. To protect the storage fluorescent screen contained in the cassette against unintentional exposure and from contamination and damage, the known cassette is provided at its opening with a closure which is displaceable between a closed position in which it closes the opening and a release position in which it releases the opening for insertion or removal of the storage fluorescent screen. In this case a cover strip extending the length of the opening and provided at each end with a bearing plate, which in turn is pivoted in the cassette, is used as the closure. To operate the closure an operating mechanism which can be displaced inside the cassette from outside by the actuating element is contained in the cassette.
The disadvantage of this known cassette is that the opening is of comparatively small dimensions because of the nature of the pivoted closure mounting, whereby insertion of the storage fluorescent screen in the cassette and removal of same from the cassette are made difficult.
U.S. Pat. No. 5,441,251 discloses a cassette for receiving a storage fluorescent screen. In this case the base of the cassette is divided into two sections, one of the sections being attached swivellably to the other section and being swivellable up to open the cassette so that the storage fluorescent screen can be inserted in the cassette or removed therefrom.
A major disadvantage of this known cassette is that the base section to be opened requires a large swivelling area in order to remove the storage fluorescent screen from, or insert the storage fluorescent screen into, the cassette. Because a cassette is normally opened only inside a device, for example, a readout device, a correspondingly large swivelling area is required in the device so that the cassette can be opened.